Climate change and its effect on agriculture, water resources and human health sectors in Poland

Multi-model ensemble climate projections in the ENSEMBLES Project of the EU allowed the authors to quantify selected extreme-weather indices for Poland, of importance to climate impacts on systems and sectors. Among indices were: number of days in a year with high value of the heat index; with high maximum and minimum temperatures; length of vegetation period; and number of consecutive dry days. Agricultural, hydrological, and human health indices were applied to evaluate the changing risk of weather extremes in Poland in three sectors. To achieve this, model-based simulations were compared for two time horizons, a century apart, i.e., 1961–1990 and 2061–2090. Climate changes, and in particular increases in temperature and changes in rainfall, have strong impacts on agriculture via weather extremes – droughts and heat waves. The crop yield depends particularly on water availability in the plant development phase. To estimate the changes in present and future yield of two crops important for Polish agriculture i.e., potatoes and wheat, some simple empirical models were used. For these crops, decrease of yield is projected for most of the country, with national means of yield change being: –2.175 t/ha for potatoes and –0.539 t/ha for wheat. Already now, in most of Poland, evapotranspiration exceeds precipitation during summer, hence the water storage (in surface water bodies, soil and ground) decreases. Summer precipitation deficit is projected to increase considerably in the future. The additional water supplies (above precipitation) needed to use the agro-potential of the environment would increase by half. Analysis of water balance components (now and in the projected future) can corroborate such conclusions. As regards climate and health, a composite index, proposed in this paper, is a product of the number of senior discomfort days and the number of seniors (aged 65+). The value of this index is projected to increase over 8-fold during 100 years. This is an effect of both increase in the number of seniors (over twofold) and the number of senior-discomfort days (nearly fourfold)

The future of Viscum album L. in Europe will be shaped by temperature and host availability.

Viscum album L. is a plant of great importance due to its influence on the host trees and, by extension, entire ecosystems. The species is also significant to humans-on the one hand, because of its use in medicine, and on the other, because of the growing threat it poses to the stability of conifer stands. Therefore, it is important to recognize the future range of three mistletoe subspecies (Viscum album subsp. album, V. album subsp. austriacum, and V. album subsp. abietis). Modelling of the potential range of these subspecies was performed using MAXENT software. Locations were collected from literature and databases. A total number of 3335 stands were used. Bioclimatic data for the current conditions and three future scenarios (SSP 1.26, SSP 3.70, SSP 5.85) were downloaded from the CHELSA database. The results confirmed that the temperature is the key variable on the potential range of the analysed subspecies. V. album subsp. abietis is withdrawing from its range according to all scenarios. In the case of V. album subsp. austriacum, a slight range shift is visible. Only the V. album subsp. album will expand non-directionally. The reason is most likely a very large number of host species and greater genetic variability compared to the subspecies found on conifers

Electrical switching of a chiral lasing from polariton condensate in a Rashba-Dresselhaus regime

Efficient optical classical and quantum information processing imposes on light novel requirements: chirality with low threshold non-linearities. In this work we demonstrate a chiral lasing from an optical modes due to emerging photonic Rashba-Dresselhaus spin-orbit coupling (SOC). For this purpose we developed a new electrically tunable device based on an optical cavity filled with birefringent liquid crystal (LC) and perovskite crystals. Our novel method for the growth of single crystals of CsPbBr$_3$ inorganic perovskite in polymer templates allows us to reach a strong light-matter coupling regime between perovskite excitons and cavity modes, and induce polariton condensation. The sensitivity of the LC to external electric fields lets us to tune the condensate energy in situ and induce synthetic SOC. This shapes the condensate between a single linearly polarized or two circularly polarized separated in momentum, emitting coherent light. The difference in the condensation thresholds between the two SOC regimes can be used to switch on and off the chiral condensate emission with a voltage.Comment: 8 pages, 5 figure

No systematic effects of sampling direction on climate-growth relationships in a large-scale, multi-species tree-ring data set

Ring-width series are important for diverse fields of research such as the study of past climate, forest ecology, forest genetics, and the determination of origin (dendro-provenancing) or dating of archaeological objects. Recent research suggests diverging climate-growth relationships in tree-rings due to the cardinal direction of extracting the tree cores (i.e. direction-specific effect). This presents an understudied source of bias that potentially affects many data sets in tree-ring research. In this study, we investigated possible direction-specific growth variability based on an international (10 countries), multi-species (8 species) tree-ring width network encompassing 22 sites. To estimate the effect of direction-specific growth variability on climate-growth relationships, we applied a combination of three methods: An analysis of signal strength differences, a Principal Component Gradient Analysis and a test on the direction-specific differences in correlations between indexed ring-widths series and climate variables. We found no evidence for systematic direction-specific effects on tree radial growth variability in high-pass filtered ring-width series. In addition, direction-specific growth showed only marginal effects on climate-growth correlations. These findings therefore indicate that there is no consistent bias caused by coring direction in data sets used for diverse dendrochronological applications on relatively mesic sites within forests in flat terrain, as were studied here. However, in extremely dry, warm or cold environments, or on steep slopes, and for different life-forms such as shrubs, further research is advisable.</p

Problems of data interpretation of the selected devices recording vehicles movement parameters

W artykule zestawiono niektóre rodzaje urządzeń, służących do pomiarów parametrów ruchu pojazdów, mierzących w sposób bezpośredni różne wielkości fizyczne. Omówiono sposób rejestracji danych przez czujniki przyspieszeń z elektronicznymi żyroskopami, stosowanymi między innymi w samochodowych "czarnych skrzynkach". Przeprowadzona została analiza sygnałów z ww. czujników, poprzedzona badaniami symulacyjnymi i eksperymentalnymi. W przypadku obu rodzajów badań, podejmowano próby odtwarzania toru ruchu środka masy samochodu, na podstawie uprzednio wyznaczonych (w symulacyjnym programie komputerowym) lub zmierzonych (w rzeczywistym eksperymencie) przyspieszeń i prędkości kątowych. Wyniki badań wskazały na istniejące obecnie ograniczenia w zakresie stosowania czujników do odtwarzania parametrów ruchu pojazdów, co uzasadnia konieczność prowadzenia dalszych poszukiwań w celu wyjaśnienia przyczyn oraz minimalizację zaobserwowanych błędów.In the paper there were compared some of the types of devices used for measuring vehicles movement parameters, which in direct way measure various physical parameters. There was discussed, how data are registered by acceleration sensors with electronic gyroscopes, used among others in the automotive "black boxes". There was carried out the signal analysis from above mentioned sensors, followed by making simulation and experimental research. For both types of studies, there were made the attempts to reconstruct the motion of the mass center of a car, on the basis on pre-assigned (in a simulation computer program) or measured (in a real experiment) acceleration and angular velocity values. The results indicated the existing restrictions in usage of sensors to make reconstruction of vehicle movement parameters, justifying the need for further research to clarify the causes and minimize the observed errors

Dying of ash (Fraxinus excelsior L.) in the Jesionowe Gory Nature Reserve

The aim of this study was to analyse changes in the health status of ash stands belonging to the age classes VI and VIII growing in optimal site conditions and to compare the ash dieback with other age classes in the Jesionowe Góry Nature Reserve. Our research was conducted during the growing season in 2006 and 2007 on 22 permanent and 54 temporary sample plots. The health condition of the stands and the structure of natural regeneration were determined with a one-year interval. The amount of damage was defined using leaf loss, pest infestation and shoot dieback. Based on our estimation of natural regeneration, the capability for stand evolution in the future was determined

Proposition of a large-scale mistletoe inventory method

Mistletoe (Viscum album L.) is a semi−parasitic plant and, as long as it is not present in large quantities, it does not pose a lethal threat to trees. Due to its ability to carry out photosynthesis, its effect on the host is negligible. However, recent droughts have made heavy impact on forests and mistletoe in recent years began to appear on a larger scale in regions and in places where it has never been a threat before. For this reason, there is an urgent need to broaden our knowledge about this species. This work includes a review of the literature on the biology and ecology of mistletoe. The main purpose of this research is to analyze the methods for assessing the number of mistletoe on individual trees and in the stands as well as to prepare new method adapted to Polish conditions. New method that was proposed is based on random sample plots, each consisting of 15 trees on which impact of mistletoe is assessed. On every sample plot the mistletoe occurrence, location in the crown, estimate of the percentage within the crown and the number of mistletoe on a tree is assessed. In addition, for further analysis, information on stand (forest habitat type, site index) as well as measured trees (age, diameter, Kraft class, crown length, loss of assimilation apparatus, crown type) levels is recorded

Forest stands acquired from the State Land Fund – the condition and management problems

In this paper, we present problems with the management of the forests acquired by the State Forests from the State Land Fund. This was particularly an issue in forest districts with a significant share of private forests, e.g. eastern part of Poland. The problem becomes more and more valid because of the latest amendment of the Forest Act in 2016. It gives the State Forests the right of the first purchase of private forests attributed to sale. They may receive forest stands that will generate specific economic problems related to care, conservation, felling maintenance, etc. These are mostly stands with typical features of private forests, resulting from abandoning economic operations, selective acquisition, as well as from the size, shape and neighbourhood of the plots. This study presents the characteristics of almost 2,000 tree stands acquired from the State Land Fund between 1992−2016 by the Siedlce Forest District (SFD), which is a part of the Regional Directorate of the State Forests in Warsaw. SFD has low forest cover (18%), a strong fragmentation of forest complexes and a very large share of private forests (over 75%). The analysis was based primarily on the descriptions of forest stands and the quantitative and qualitative characteristics, presenting at the same time the problems that SFD has with conducting rational forest management in acquired plots. The current status of the forests transferred from the State Land Fund was assessed as unsatisfactory. The main problems in local conditions are: (i) inadequate fixation in acquired parcels next to private forests (difficulty in locating treatments and custody over the State property), (ii) depleted tree stands, (iii) inadequate parcels (too narrow) and (iv) complications related to co−ownership of parts seized plots. The need to carry out joint−assembly works (mainly land consolidation) or to introduce land communities that would facilitate the management of these forests was demonstrated